Over 120 aftershocks rattle Northern California coast following 7.0 earthquake
Aftershocks continued to rattle the North Coast Thursday night into Friday morning following the powerful 7.0 earthquake that prompted a tsunami warning across a large stretch of California.
More than 120 aftershocks and quakes over magnitudes 2.5 have followed since the larger shaker struck Thursday morning, according to the U.S. Geological Survey, with up to four or five aftershocks per hour happening. Dozens of smaller aftershocks have also been detected.
The epicenter of Thursday's 7.0 magnitude shaker happened in what's known as California's "earthquake country" because it's where three tectonic plates meet. The temblor was the most powerful to rattle the state since a 7.1-magnitude quake hit Ridgecrest in 2019.
The initial large earthquake struck at 10:44 a.m. off Cape Mendocino in Humboldt County. The quake was strong enough to trigger a tsunami warning from the National Weather Service, but the warning was canceled 70 minutes after it was issued when no serious tsunami threat was detected.
According to the USGS, there is a 53% chance for one or more aftershocks larger than magnitude 5 within the next week.
"There will likely be smaller aftershocks within the next week, with up to 130 magnitude 3 or higher aftershocks," according the the USGS website's aftershock forecast page.
"The number of aftershocks will decrease over time, but a large aftershock can temporarily increase the number of aftershocks."
While there were no reports of major damage in Humboldt County, for people in the community of Ferndale, cleaning up from a significant earthquake in December has seemingly become a tradition in recent years.
Thursday's magnitude 7.0 was the latest to strike the area around the holidays and the third in the last four years.
On Friday morning, the National Weather Service Bay Area X account posted about issuing the warning to address the agency's process, noting "there are lot of questions, frustration, and even some anger about how it all unfolded."
The thread on X addressed the different type of alerts issued for tsunamis and explained that with local tsunamis there is limited time to work with "and the warning must be issued with more uncertainty in order to allow the maximum possible evacuation window." Only five minutes passed between the time of the 7.0 earthquake and the National Tsunami Warning Center issuing the warning.
"The downside of this speed requirement is that the NTWC does not have the luxury of waiting to actually observe a tsunami wave before the first warning is needed," the post read. "They can only confirm that with deep ocean buoys and coastal observations."
